We demonstrated the conjugative transfer of plasmid pTO1 from Escherichia coli S17-1 to different Rhodococcus spp. The plasmid contains tile oriT fragment from RK2 and a fragment of Streptomyces phi C31 actinophage with the attachment site and the integration genes, Experiments on hybridization showed that plasmid pTO1 is chromosomally integrated into the Rhodococcus cells.